- Email: [email protected]
SYMPHYSIOTOMY AND VACUUM EXTRACTION
396
grandson, with all modem methods of resuscitation available, died following cardiac arrest. HONEY and TRUELOVE,11 in defining a hospital mortality of 36%, observed that the greatest risk of death lies in the first twenty-four hours after the onset of symptoms, disturbances of rhythm being largely responsible. 12,lS Consequently, special units were developed in which patients could be monitored during this period of maximum risk. In the ten years since SHILLINGFORD and THOMAS 14 described the earliest such unit in the U.K. there has been a considerable proliferation of these units, and hospitals have amassed enormous quantities of resuscitation equipment. Within two years PANTRIDGE 15 was a domiciliary resuscitation service-feasible in an urban centre with a population within easy reach of the hospital, but impractical in the larger rural areas. While such a service can undoubtedly save lives, the speed of arrival is of paramount importance. A survey 16 of all reported units in the U.K. shows that only one-the Brighton unit manned by ambulance personnel-arrives within one hour of the call. Others arrive after one to six hours. Only if the main mortality is after their time of arrival can such services be justified. If the principal mortality is before the possible arrival, a mobile unit is a dramatic, exciting, and extravagant luxury. Are coronary care units necessary ? Will those
hospital those patients who are at greatest risk, concentrating all hospital resources on their management, and returning them home at the earliest time consistent with safety.22 This approach is logical and desirable; but its merits can be determined only by further clinical trials. The correct management of coronary thrombosis is not yet visible through the persisting cloud, but it is heartening that so many clinicians now follow AsHER’s advice 23 and keep KIPLING’S Six Honest Servine Men:
keep Six honest serving men (They taught me all I knew) Their names are What and Why
I
advocating
hospitals which, through poverty, apathy, or both, have been deprived of such units, come to be regarded as fortunate ? They have absorbed so much energy and manpower that their dissolution seems unlikely. Yet there are many patients with coronary thrombosis who have no need of intensive treatment. Some still spend the conventional 10-14 days in hospital after a typical attack of chest pain, associated with minor electrocardiographic change and possibly no change in transaminase level, though the mortality 17 and their need for among such patients is low is admission negligible. The Bristol 18 trial hospital has already shown a better prognosis for many patients who have their coronary thrombosis treated at home and who escape the rigours of ambulance journey and hospital treatment. It is becoming possible to assess the likely prognosis of a coronary thrombosis.19-21 Surely we should now be admitting to 11. 12. 13. 14. 15. 16. 17.
18.
19. 20. 21.
Honey, G. E., Truelove, S. C. Lancet, 1957, i, 1155, 1209. Wahlberg, F. Am. Heart J. 1963, 65, 749. Julian, D. G., Valentine, P. A., Miller, G. C. Med. J. Aust. 1964, i, 427. Shillingford, J. P., Thomas, M. Lancet, 1964, ii, 1113. Pantridge, J. F., Geddes, J. S. ibid. 1966, i, 807. Orchard, T. J. ibid. Feb. 16, 1974, p. 263. Marrott, P., Chopra, M. P., Portal, R. W., Aber, C. P. Br. Heart J. 1973, 35, 1240. Mather, H. G., Pearson, N. G., Read, K. L. Q., Shaw, D. B., Steed, G. R., Thorne, M. G., Jones, S., Guerrier, C. J., Eraut, C. D., McHugh, P. M., Chowdhury, N. R., Jafary, M. H., Wallace, T. J. Br. med. J. 1971, iii, 334. Peel, A. A. F., Semple, T., Wang, J., Lancaster, W. M., Dall, J. L. G. Br. Heart J. 1962, 24, 745. Thompson, P. L., Sloman, G. Ass. clin. Res. 1971, 3, 377. Norris, R. M., Brandt, P. W. T., Caughey, D. E., Lee, A. J., Scott, P. J. Lancet, 1969, i, 274.
and When
And How and Where and Who.
SYMPHYSIOTOMY AND VACUUM EXTRACTION
MOST medical schools teach European medicine, but the world population is far more widely spread. Some procedures long abandoned by well-equipped centres may still be helpful when conditions are less favourable. One such may be symphysiotomy, which for the past twenty years has been considered by the Western medical schools to be an operation of desperation. Alan Browne, the ex-Master of the Rotunda, in Dublin, used to say that the main barrier against symphysiotomy was in the minds of obstetricians; the operation is still performed regularly and successfully in the third world to treat cephalopelvic disproportion by increasing the capacity of the pelvis. Disproportion is a great problem in underdeveloped countries, where many mothers suffer the later effects of malnutrition in childhood; this situation may be made worse by the larger babies now produced by improvement in standards of living and by better feeding of mothers during pregnancy. 24 The introduction of vacuum extraction has added a means of reinforcing the expulsive powers of the uterus, and symphysiotomy should be reassessed in the light of this. The major barriers in the minds of obstetricians are fears in the short term of urinary damage and in the long term of orthopaedic complications. Proponents of symphysiotomy point out that the operation takes only a few minutes, that it can be done by the less experienced operator under local anaesthesia, and that the patient faces her next pregnancy with an intact uterus and a slightly enlarged pelvis. Vacuum extraction, in addition, provides a method of traction for the fetus without the instrument taking up space in the pelvis. It has an inbuilt safety factor, for the cap comes off if traction is too strong. This method also enables occipitotransverse and occipitoposterior positions to be delivered without the intrapelvic space being encroached upon by a hand or forceps, and is ideal for the less experienced operator. The population for whom symphysiotomy and vacuum extraction may be useful is different from that 22. 23. 24.
Wilson, C., Pantridge, J. F. ibid. 1973, ii, 1284. Richard Asher Talking Sense (edited by F. Avery Jones ; p. 54. London, 1972. Sambi, J. S. Int. J. Gynœc. Obstet. 1973, 11, 51.
397
found in the Western world. Many African women are admitted to obstetric units in established and obstructed labour. Eclampsia is common, and maternal and
perinatal mortalities are high. In such countries, symphysiotomy and vacuum extraction has been used to avoid multiple caesarean sections, but few properly conducted follow-up studies have been done. Hartfield 11 followed up 88 out of 137 women 2 had urinary fistulx which had healed so treated. spontaneously, and 3 had residual stress incontinence. A further 3 women had some orthopaedic symptoms, but, in 2 of these, symptoms appeared only in a subsequent pregnancy. 25 There were no maternal deaths associated with the symphysiotomy and, in view of the adverse conditions under which Hartfield was working, one wonders if the follow-up of 137 caesarean sections would have shown such good results. Gordon, from the in 1969, reporting Baragwanath Hospital recorded similar results.26 Of 201 women treated in labour by symphysiotomy, 2 had vesicovaginal fistulas, none had stress incontinence by six weeks, and only 1 had pain on walking. Symphysiotomy has been put to one side because surgical and medical developments have made csesarean section more attractive. In a hospital with good anxsthetic cover and properly equipped operatingtheatres this may be so, but much of the world lives beyond such facilities. It may be that symphysiotomy in combination with vacuum extraction now falls into a different at-risk category from symphysiotomy aided only by the contractions of a tired uterus, and that the urinary and orthopxdic hazards have been exaggerated. Certainly those going beyond the reaches of the safer, well-equipped labour ward may need to learn about this combination of procedures. MODERN METHODS OF BACTERIAL CLASSIFICATION THE analysis, by pyrolysis gas-liquid chromatography (P.G.L.C.) and mass spectrometry, of bacteria for chemical compounds that are unique to them provides a new approach to the classification and identification of bacteria. This use of P.G.L.C. was first described by Reiner 27 in 1965, and subsequent work by Reiner’s group 28-sgand by others 34-38 has demonstrated the value of this technique for the typing of a wide range of bacteria and for the diagnosis of viral and fungal diseases in plants. The method is based on the thermal degradation of a small sample of the dried bacterium under carefully controlled conditions and the separation of the resulting break25. Hartfield, V. J. Aust. N.Z. Jl Obstet. Gynœc. 1973, 13, 147. 26. Gordon, Y. B. S. Afr. med. J. 1969, 43, 659. 27. Reiner, E. Nature, 1965, 206, 1272. 28. Reiner, E. J. Gas Chromatogr. 1967, 5, 65. 29. Reiner, E., Ewing, W. H. Nature, 1968, 217, 191. 30. Reiner, E., Kubica, G. P. Am. Rev. resp. Dis. 1969, 99, 42. 31. Reiner, E., Beam, R. E., Kubica, G. P. ibid. p. 750. 32. Menger, F. M., Epstein, G. A., Goldberg, D. A., Reiner, E. Analyt. Chem. 1972, 44, 423. 33. Reiner, E., Hicks, J. J., Ball, M. M., Martin, W. J. ibid. p. 1058. 34. Simmonds, P. G. Appl. Microbiol. 1970, 20, 567. 35. Vincent, P. G., Kubits, M. M. ibid. p. 957. 36. Meuzelaar, H. L. C., in’t Veld, R. A. J. chromatogr. Sci. 1972, 10, 213. 37. Haddadin, J. M., Stirland, R. M., Preston, N. W., Collard, P. Appl. Microbiol. 1973, 25, 40. 38. Myers, A., Watson, L. Nature, 1969, 223, 964.
down products by gas-liquid chromatography. Each bacterial strain produces a characteristic fragment chromatogram (pyrochromatogram) which is used as a fingerprint " to identify the microorganism. Automatic recognition of bacterial types by computer matching of the pyrochromatograms has been described —indeed, the whole technique, including sample loading and analysis, is ideally suited to automation. However, although several workers have described the successful application of P.G.L.C. to classification problems, the qualitative and quantitative differences between pyrochromatograms from different species are small. Because of this, even though most workers claim good reproducibility, confidence in such results cannot be high. For example, it might be expected that such small differences would be very susceptible to changes in the conditions and period of growth of the microorganism and would demand a high level of reproducibility in the pyrolysis conditions. 38 The most satisfactory gas-chromatographic results in this type of application are obtained by the use of high-efficiency capillary columns. 114, 3 These columns, which are being used for the quantitative analysis of biological extracts,39 permit the complete separation of a very large number of components of a complex mixture, and give better resolution of components diagnostic for one bacterial species. Analytical power may be further improved by the use of coupled gaschromatography/mass-spectrometry.400 Here the mass spectrometer acts as gas-chromatographic detector so that the chemical structure of compounds eluted from the gas chromatograph can be determined. Thus the addition of the mass spectrometer provides a more reliable and characteristic means of identification of eluted materials than simple measurement of gaschromatographic retention-times. If it is found that it is the amount of certain compounds in the pyrolysis products that is the best indicator of bacterial species, then the mass spectrometer can be set to act as a specific and quantitative detector for these compounds by only monitoring ions of selected masses. What is needed now is a systematic comparison of bacterial "
pyrolysis products using temperature-programmed capillary gas-chromatography/mass-spectrometry paying special attention to the development of standard conditions for analysis and to the effect of varying growth conditions. As an alternative to the P.G.L.C. technique, the samples can be subjected to mild pyrolysis in the mass spectrometer itself without any intervening gaschromatographic separation. The direct introduction of the dried bacterium into the ion source of the mass spectrometer at 250-300 °C produces some degree of thermal degradation, and the mass spectrometer may then be used to record ions characteristic of certain classes of compounds in the bacterium. The possible advantage of this technique lies in the in-situ production and analysis of compounds that are not amenable to gas-chromatographic analysis because of their high molecular weight or polarity but which, for 39. Bailey, E., Fenoughty, M., Chapman, J. R. Unpublished. 40. McFadden, W. H. Techniques of Combined Gas ChromatographyMass Spectrometry: Applications in Organic Analysis. New York, 1973.
grandson, with all modem methods of resuscitation available, died following cardiac arrest. HONEY and TRUELOVE,11 in defining a hospital mortality of 36%, observed that the greatest risk of death lies in the first twenty-four hours after the onset of symptoms, disturbances of rhythm being largely responsible. 12,lS Consequently, special units were developed in which patients could be monitored during this period of maximum risk. In the ten years since SHILLINGFORD and THOMAS 14 described the earliest such unit in the U.K. there has been a considerable proliferation of these units, and hospitals have amassed enormous quantities of resuscitation equipment. Within two years PANTRIDGE 15 was a domiciliary resuscitation service-feasible in an urban centre with a population within easy reach of the hospital, but impractical in the larger rural areas. While such a service can undoubtedly save lives, the speed of arrival is of paramount importance. A survey 16 of all reported units in the U.K. shows that only one-the Brighton unit manned by ambulance personnel-arrives within one hour of the call. Others arrive after one to six hours. Only if the main mortality is after their time of arrival can such services be justified. If the principal mortality is before the possible arrival, a mobile unit is a dramatic, exciting, and extravagant luxury. Are coronary care units necessary ? Will those
hospital those patients who are at greatest risk, concentrating all hospital resources on their management, and returning them home at the earliest time consistent with safety.22 This approach is logical and desirable; but its merits can be determined only by further clinical trials. The correct management of coronary thrombosis is not yet visible through the persisting cloud, but it is heartening that so many clinicians now follow AsHER’s advice 23 and keep KIPLING’S Six Honest Servine Men:
keep Six honest serving men (They taught me all I knew) Their names are What and Why
I
advocating
hospitals which, through poverty, apathy, or both, have been deprived of such units, come to be regarded as fortunate ? They have absorbed so much energy and manpower that their dissolution seems unlikely. Yet there are many patients with coronary thrombosis who have no need of intensive treatment. Some still spend the conventional 10-14 days in hospital after a typical attack of chest pain, associated with minor electrocardiographic change and possibly no change in transaminase level, though the mortality 17 and their need for among such patients is low is admission negligible. The Bristol 18 trial hospital has already shown a better prognosis for many patients who have their coronary thrombosis treated at home and who escape the rigours of ambulance journey and hospital treatment. It is becoming possible to assess the likely prognosis of a coronary thrombosis.19-21 Surely we should now be admitting to 11. 12. 13. 14. 15. 16. 17.
18.
19. 20. 21.
Honey, G. E., Truelove, S. C. Lancet, 1957, i, 1155, 1209. Wahlberg, F. Am. Heart J. 1963, 65, 749. Julian, D. G., Valentine, P. A., Miller, G. C. Med. J. Aust. 1964, i, 427. Shillingford, J. P., Thomas, M. Lancet, 1964, ii, 1113. Pantridge, J. F., Geddes, J. S. ibid. 1966, i, 807. Orchard, T. J. ibid. Feb. 16, 1974, p. 263. Marrott, P., Chopra, M. P., Portal, R. W., Aber, C. P. Br. Heart J. 1973, 35, 1240. Mather, H. G., Pearson, N. G., Read, K. L. Q., Shaw, D. B., Steed, G. R., Thorne, M. G., Jones, S., Guerrier, C. J., Eraut, C. D., McHugh, P. M., Chowdhury, N. R., Jafary, M. H., Wallace, T. J. Br. med. J. 1971, iii, 334. Peel, A. A. F., Semple, T., Wang, J., Lancaster, W. M., Dall, J. L. G. Br. Heart J. 1962, 24, 745. Thompson, P. L., Sloman, G. Ass. clin. Res. 1971, 3, 377. Norris, R. M., Brandt, P. W. T., Caughey, D. E., Lee, A. J., Scott, P. J. Lancet, 1969, i, 274.
and When
And How and Where and Who.
SYMPHYSIOTOMY AND VACUUM EXTRACTION
MOST medical schools teach European medicine, but the world population is far more widely spread. Some procedures long abandoned by well-equipped centres may still be helpful when conditions are less favourable. One such may be symphysiotomy, which for the past twenty years has been considered by the Western medical schools to be an operation of desperation. Alan Browne, the ex-Master of the Rotunda, in Dublin, used to say that the main barrier against symphysiotomy was in the minds of obstetricians; the operation is still performed regularly and successfully in the third world to treat cephalopelvic disproportion by increasing the capacity of the pelvis. Disproportion is a great problem in underdeveloped countries, where many mothers suffer the later effects of malnutrition in childhood; this situation may be made worse by the larger babies now produced by improvement in standards of living and by better feeding of mothers during pregnancy. 24 The introduction of vacuum extraction has added a means of reinforcing the expulsive powers of the uterus, and symphysiotomy should be reassessed in the light of this. The major barriers in the minds of obstetricians are fears in the short term of urinary damage and in the long term of orthopaedic complications. Proponents of symphysiotomy point out that the operation takes only a few minutes, that it can be done by the less experienced operator under local anaesthesia, and that the patient faces her next pregnancy with an intact uterus and a slightly enlarged pelvis. Vacuum extraction, in addition, provides a method of traction for the fetus without the instrument taking up space in the pelvis. It has an inbuilt safety factor, for the cap comes off if traction is too strong. This method also enables occipitotransverse and occipitoposterior positions to be delivered without the intrapelvic space being encroached upon by a hand or forceps, and is ideal for the less experienced operator. The population for whom symphysiotomy and vacuum extraction may be useful is different from that 22. 23. 24.
Wilson, C., Pantridge, J. F. ibid. 1973, ii, 1284. Richard Asher Talking Sense (edited by F. Avery Jones ; p. 54. London, 1972. Sambi, J. S. Int. J. Gynœc. Obstet. 1973, 11, 51.
397
found in the Western world. Many African women are admitted to obstetric units in established and obstructed labour. Eclampsia is common, and maternal and
perinatal mortalities are high. In such countries, symphysiotomy and vacuum extraction has been used to avoid multiple caesarean sections, but few properly conducted follow-up studies have been done. Hartfield 11 followed up 88 out of 137 women 2 had urinary fistulx which had healed so treated. spontaneously, and 3 had residual stress incontinence. A further 3 women had some orthopaedic symptoms, but, in 2 of these, symptoms appeared only in a subsequent pregnancy. 25 There were no maternal deaths associated with the symphysiotomy and, in view of the adverse conditions under which Hartfield was working, one wonders if the follow-up of 137 caesarean sections would have shown such good results. Gordon, from the in 1969, reporting Baragwanath Hospital recorded similar results.26 Of 201 women treated in labour by symphysiotomy, 2 had vesicovaginal fistulas, none had stress incontinence by six weeks, and only 1 had pain on walking. Symphysiotomy has been put to one side because surgical and medical developments have made csesarean section more attractive. In a hospital with good anxsthetic cover and properly equipped operatingtheatres this may be so, but much of the world lives beyond such facilities. It may be that symphysiotomy in combination with vacuum extraction now falls into a different at-risk category from symphysiotomy aided only by the contractions of a tired uterus, and that the urinary and orthopxdic hazards have been exaggerated. Certainly those going beyond the reaches of the safer, well-equipped labour ward may need to learn about this combination of procedures. MODERN METHODS OF BACTERIAL CLASSIFICATION THE analysis, by pyrolysis gas-liquid chromatography (P.G.L.C.) and mass spectrometry, of bacteria for chemical compounds that are unique to them provides a new approach to the classification and identification of bacteria. This use of P.G.L.C. was first described by Reiner 27 in 1965, and subsequent work by Reiner’s group 28-sgand by others 34-38 has demonstrated the value of this technique for the typing of a wide range of bacteria and for the diagnosis of viral and fungal diseases in plants. The method is based on the thermal degradation of a small sample of the dried bacterium under carefully controlled conditions and the separation of the resulting break25. Hartfield, V. J. Aust. N.Z. Jl Obstet. Gynœc. 1973, 13, 147. 26. Gordon, Y. B. S. Afr. med. J. 1969, 43, 659. 27. Reiner, E. Nature, 1965, 206, 1272. 28. Reiner, E. J. Gas Chromatogr. 1967, 5, 65. 29. Reiner, E., Ewing, W. H. Nature, 1968, 217, 191. 30. Reiner, E., Kubica, G. P. Am. Rev. resp. Dis. 1969, 99, 42. 31. Reiner, E., Beam, R. E., Kubica, G. P. ibid. p. 750. 32. Menger, F. M., Epstein, G. A., Goldberg, D. A., Reiner, E. Analyt. Chem. 1972, 44, 423. 33. Reiner, E., Hicks, J. J., Ball, M. M., Martin, W. J. ibid. p. 1058. 34. Simmonds, P. G. Appl. Microbiol. 1970, 20, 567. 35. Vincent, P. G., Kubits, M. M. ibid. p. 957. 36. Meuzelaar, H. L. C., in’t Veld, R. A. J. chromatogr. Sci. 1972, 10, 213. 37. Haddadin, J. M., Stirland, R. M., Preston, N. W., Collard, P. Appl. Microbiol. 1973, 25, 40. 38. Myers, A., Watson, L. Nature, 1969, 223, 964.
down products by gas-liquid chromatography. Each bacterial strain produces a characteristic fragment chromatogram (pyrochromatogram) which is used as a fingerprint " to identify the microorganism. Automatic recognition of bacterial types by computer matching of the pyrochromatograms has been described —indeed, the whole technique, including sample loading and analysis, is ideally suited to automation. However, although several workers have described the successful application of P.G.L.C. to classification problems, the qualitative and quantitative differences between pyrochromatograms from different species are small. Because of this, even though most workers claim good reproducibility, confidence in such results cannot be high. For example, it might be expected that such small differences would be very susceptible to changes in the conditions and period of growth of the microorganism and would demand a high level of reproducibility in the pyrolysis conditions. 38 The most satisfactory gas-chromatographic results in this type of application are obtained by the use of high-efficiency capillary columns. 114, 3 These columns, which are being used for the quantitative analysis of biological extracts,39 permit the complete separation of a very large number of components of a complex mixture, and give better resolution of components diagnostic for one bacterial species. Analytical power may be further improved by the use of coupled gaschromatography/mass-spectrometry.400 Here the mass spectrometer acts as gas-chromatographic detector so that the chemical structure of compounds eluted from the gas chromatograph can be determined. Thus the addition of the mass spectrometer provides a more reliable and characteristic means of identification of eluted materials than simple measurement of gaschromatographic retention-times. If it is found that it is the amount of certain compounds in the pyrolysis products that is the best indicator of bacterial species, then the mass spectrometer can be set to act as a specific and quantitative detector for these compounds by only monitoring ions of selected masses. What is needed now is a systematic comparison of bacterial "
pyrolysis products using temperature-programmed capillary gas-chromatography/mass-spectrometry paying special attention to the development of standard conditions for analysis and to the effect of varying growth conditions. As an alternative to the P.G.L.C. technique, the samples can be subjected to mild pyrolysis in the mass spectrometer itself without any intervening gaschromatographic separation. The direct introduction of the dried bacterium into the ion source of the mass spectrometer at 250-300 °C produces some degree of thermal degradation, and the mass spectrometer may then be used to record ions characteristic of certain classes of compounds in the bacterium. The possible advantage of this technique lies in the in-situ production and analysis of compounds that are not amenable to gas-chromatographic analysis because of their high molecular weight or polarity but which, for 39. Bailey, E., Fenoughty, M., Chapman, J. R. Unpublished. 40. McFadden, W. H. Techniques of Combined Gas ChromatographyMass Spectrometry: Applications in Organic Analysis. New York, 1973.